Mooring arrangements for ships



Nov. 3, 1964 J. w. Ross ETAL MOORING ARRANGEMENTS FOR SHIPS Filed Aug. 13, 1963 2 Sheets-Sheet 1 INVENTORS JOHN WILLIAM ROSS KENNETH WILLIAM HOPKINS av WW /11, fizujm, @rm {fine ATTORN EYS Nov. 3, 1964 J. w. R088 ETAL' MOORING ARRANGEMENTS FOR SHIPS 2 Sheets-Sheet 2 Filed Aug. 13, 1963 Alva/foes: Jomv Iv/1. 1.14M 058 ken/#67 Wu 14M Hone/Ms United States Patent 3,155,669 MGDRING ANGEMENTS FOR SHIPS John Wiliiarn Ross and Kenneth William Hopkins, London, England, assignors to 13.1 Tanker Company Limited, London, England, a British joint-stock corporation Filed Aug. 13, 1963, Ser. No. 301,870 Claims priority, application Great Britain, Aug. 17, 1962, 31,642/ 62 8 Claims. (Cl. 114-230 This invention relates to mooring arrangements for ships and particularly single point mooring arrangements for tank ships.

With the advent of so called supertankers, tank ships of 50,000 d.w.t. and above, it is becoming increasingly difficult to find harbours which have sufiicient depth to allow such ships to berth.

To overcome this difficulty it has been proposed to moor such ships to buoys to allow loading and unloading of the liquid cargo via the buoys. With such an arrangement a ship is usually moored by a cable which extends from the bow to the buoy, flexible hoses being provided for loading and unloading, the ship being allowed to rotate 360 around the buoy at will, according to tide and wind etc. However this arrangement suffers from the serious disadvantages that in bad weather the ship can easily part the mooring cable, and with conditions of swell the ship can foul the buoy and the flexible hoses from the ship to the buoy which carry the liquid cargo.

It is an object of the present invention to obivate such difiiculties.

According to the present invention, we provide a mooring arrangement for a ship comprising a floatable member adapted to be petitioned in the water so as to be capable of rotating about a horizontal axis and means for mooring said member to the ship, all in such manner that, when the ship tends to move in a direction away from the floating member, the latter rotates about said horizontal axis to allow such movement.

Conveniently the lioatably member can be arranged to be rotatable about a horizontal axis by rotatably mounting the member on a device which is adapted to be mounted on a buoy moored to the sea bed.

The device may have two longitudinally extending members between which the floatable member is rotatably mounted. These longitudinal members may be arranged, in use, to extend one along each side of the ship, the ship also being moored to these members in such manner that movement of the ship away from the floatable member is not impeded and that the ship is restrained from such movement towards the floatable member that would cause the ship to foul the floatable member.

A resilient member may be connected between the two longithdinal members in such manner that if, in use, the further mooring means are broken the ship is restrained from fouling the floatable member.

The longitudinal members may also be adapted to comprise supports for carrying pipes, or be formed as pipes, so that, in use, a liquid cargo can be transferred between a tank ship and the buoy without the pipe connections between the ship and the buoy becoming entangled.

Conveniently the floatable member may be hollow and may be a right circular metal cylinder which is weighted, for example by concrete, at one end.

In order that the invention can be more easily understood a specific embodiment Will now be described, by way of example only, with reference to the accompanying drawings, in which:

FIGURE 1 shows a side view of a ship moored by a buoy;

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FIGURE 2 shows a plan view of FIGURE 1;

FIGURE 3 shows a perspective view of the mooring arrangement of FIGURES 1 and 2, on a larger scale.

Referring to the drawings, there is shown a floatable member 11 rotatably mounted on lugs 12 carried by longitudinally extending members 13. The floatable member 11 comprises a metal cylinder weighted at one end by concrete 14 (FIG. 1).

A ship 15 is moored by two cables 16 to a hook 17 carried by member 11.

The longitudinal members 13 are welded toa U-shaped member 18 which is rotatably mounted on a buoy 19.

The buoy 19 comprises a float chamber 20 supporting a vertical member 21 to which the U-shaped member 18 is rotatably connected. Four triangular members 22 are welded to the lower portion of member 21, these members 22 being secured to the sea bed by a cable arrange meat 23.

The longitudinal members 13 are strengthened by metal struts 24- which are welded to the members 13. A resilient member 25 is positioned between the longitudinal members 13, on the opposite side of the floatable member 11 to the buoy 19. The ship 15 is also moored by cables 26 to the longitudinal members 13.

The operation of the mooring arrangement is as follows; with the ship 15, moored as shown in the drawings, the effect of tide and wind is to cause the ship 15 to rotate round the buoy 19 to be substantially parallel with the direction of the wind or tide. With rough seas, or swell conditions, the ship 15 may surge in a direction away from the buoy 19. When this occurs, the floatable member 11 will rotate, the ship tending to raise the weighted portion 14- from the water. The floatable member 11 will then turn towards its vertical position and restore the ship to its moored position. If the ship tends to move towards the floatable member 11, it will be restrained by the cables 26. The resilient member 25 is provided to prevent the ship 15 from damaging the floatable member 11 if the cables 26 should part.

When the ship 15 is a tank ship, it may be loaded by passing the liquid cargo from land through pipelines 27 on the sea bed. The pipelines 27 are connected to the lower end of member 21, so that the liquid passes through member 21. The liquid passes from manifold 29 into the longitudinal members 13 which are formed as pipes, or through pipes 31 carried by member 13. The liquid then passes into flexible hoses 30, which extend along the side of the ship 15, or over the bow and then into the cargo tanks. Unloading of the tank ship is achieved by causing the liquid cargo to pass in the opposite direction to that described above for loading.

We claim:

1. A mooring arrangement for a ship comprising a fixed member, a floatable member adapted to absorb energy when said member is tilted about a horizontal axis, a longitudinally extending member adapted to support, in use, said floatable member between said fixed member and the ship, means for flexibly connecting said floatable member to said longitudinally extending member so that the floatable member is capable for rotating about a horizontal axis, and means connectible with said floatable member in vertically spaced relation to said horizontal axis, for attaching the ship to said floatable member so that when, in use, the ship tends to move in a direction away from the floatable member, said floatable member may be caused to rotate by said attaching means about said horizontal axis to allow such movement with absorption of energy.

2. A mooring arrangement as claimed in claim 1 which comprises two longitudinally extending members, between which the floatable member is rotatably mounted.

3. A mooring arrangement as claimed in claim 2 wherein the longitudinal members are arranged so that, in use, they extend one along each side of the ship, so that the ship can be moored to these longitudinal members in such manner that movement of the ship away from the floatable member is not impeded by said longitudinal members, and wherein restraining means associated with said longitudinal members are provided between said fioatable member and the ship so that the ship is restrained from movement towards the floatable member that would cause the ship to foul the floataole member.

4. A mooring arrangement as claimed in claim 3 wherein said restraining means comprises a resilient member connected between the two longitudinal members.

5. A mooring arrangement as claimed in claim 4 wherein the longitudinal members are flexibly connected to said fixed member and are formed so as to comprise supports for carrying pipes so that, in use, a liquid cargo can be transferred between a tank ship and the fixed member without the pipe connections between the ship and the fixed member becoming entangled.

6. A mooring arrangement as claimed in claim 5 wherein the longitudinal members are formed as pipes so that, in use, a liquid cargo can be transferred between a tank ship and the fixed member without pipe connections between the ship and the fixed member becoming entangled.

7. A mooring arrangement as claimed in claim 6 wherein the fioatable member is a hollow cylinder which is weighted at one end.

8. A mooring system, as claimed in claim 1, wherein the fixed member is a buoy moored to the sea bed.

References Cited by the Examiner UNITED STATES PATENTS 1,828,821 10/31 Short et a1. 114230 1,921,500 8/23 Blake 98 1,074,082 1/63 Griebe 114-230 3,093,167 6/63 McCammon 1l4230 FERGUS S. MIDDLETON, Primary Examiner.

UNITED STATES PA ENT o FiCE CERTIFICATE I or CORRECTION Patent No'. 3,155,069 d November 5, 1964 v John William. Ross et a1. v

It is hereby certified that error appears in the above numbered patent requiring correction and that the said Letters Patent should read as corrected below. i v

In the grant, lines 2 and 12, and in the. heading to the printed specification, lines 4 and 5, name ofassignee, for "B. P. Tanker Company Limited", each occurrence, read BP Tanker Company Limited column 1, line 30, for

"obivate" read obviate line 34, for "petitioned" read positioned same column 1, line 40, for "float'ablgfl read floatable column 2, line 46, for "member" read members column 4, line 17, for "8/23" read 8/33 line 18, for "1,074,082". read 3,074,082

Signed and sealed this 20th day of April 1965.

(SEAL) Attest:

ERNEST w. SWIDER a EDWARD J. BRENNER Attesting Officer Commissioner of Patents 

1. A MOORING ARRANGEMENT FOR A SHIP COMPRISING A FIXED MEMBER, A FLOATABLE MEMBER ADAPTED TO ABSORB ENERGY WHEN SAID MEMBER IS TILTED ABOUT A HORIZONTAL AXIS, A LONGITUDINALLY EXTENDING MEMBER ADAPTED TO SUPPORT, IN USE, SAID FLOATABLE MEMBER BETWEEN SAID FIXED MEMBER AND THE SHIP, MEANS FOR FLEXIBLY CONNECTING SAID FLOATABLE MEMBER TO SAID LONGITUDINALLY EXTENDING MEMBER SO THAT THE FLOATABLE MEMBER IS CAPABLE FOR ROTATING ABOUT A HORIZONTAL AXIS, AND MEANS CONNECTIBLE WITH SAID FLOATABLE MEMBER IN VERTICALLY SPACED RELATION TO SAID HORIZONTAL AXIS, FOR ATTACHING THE SHIP TO SAID FLOATABLE MEMBER SO THAT WHEN, IN USE, THE SHIP TENDS TO MOVE IN A DIRECTION AWAY FROM THE FLOATABLE MEMBER, SAID FLOATABLE MEMBER MAY BE CAUSED TO ROTATE BY SAID ATTACHING MEANS ABOUT SAID HORIZONTAL AXIS TO ALLOW SUCH MOVEMENT WITH ABSORPTION OF ENERGY. 